Method of treating grain fruit, especially bread grain



Oct. 21, 1952 K- DIENST ETAL 2,614,935

METHOD TREATING GRAIN FRUIT, ESPECIALLY BREAD GRAIN Filed Dec. 6, 1950WWW,

Patented Oct. 21, 1952 OFFICE i METHOD, ORTREATING GRAIN FRUIT,ESPECIALLY BREAD-GRAIN Karl Dienst and Waldemar Dienst, I 3 Hildesheim,Germany Application December a, 1950, Serial No. 199,420

, Switzerland October 19, 1950,

* e Claims. (01. 99-30) This invention relates to ,a method 10ftreatjing grain fruit,f 'especially bread grain; andfit is on'e ofthefpbiects of the inventicn to devise a method which can be varied soas to make it applicable for grain fruits of diflerent kinds and for avariety of individual treatments which the grain mustundergo to obtainthevarious products adapted to be made from the grain. r The method] inbeing carried outmakes use of a number of known, but partly improveddevices and more particularly of an improvedvacuum apparatusthat mayberegarded as a vacuum trickling drier, which devices are combined inone common plant. This plant is so con: structedthatcertainof itspartscan be bridged for allowing the various materials to be treated me,continuous operation in the most ,advantageousway. i

Themostimportant requirement of the, treatment of, "grain fruit is asubstantially perfect equalization of the moisture vcontent 'of thaindividual grains, for example, ofa grain mixture,

which are more or, less moist, in accordance with the different harvestconditionsi Hitherto, for attaining the desired moisture,

equalization the grain mixtures were stored for days in silos inwhich'theywer e repeatedly moved from one compartment to another and thewhile subjected ,or not subjected to wettingoperations.

The resultsof this knownlmethod are impaired by the fact that the grainmiXtures, which are,

for instance, designed to be treated in a mill,, constantly changebothas regards their char-R acteri and the percentageof, theirconstituents In addition, the climatic conditiona-the tempera- I ture ofthe air and the relative humidity of the air continuously change too Itis wellrknown that heat, moistureand time are the most important factorsin the equalization of/the moisture, and it is a known fact, that intthecold of .the winter an equalization of the moisture cannot be attainedat all andthe mills, are then,

run at a loss. Moisture equalization is, however; attained in an almosterfect degree, if thevac uum trickling drier is used for equalizing thedifferences of moisture of the individual grains,

provided its use takes place in the last stage of the. series ofoperations.

With the wetting method employed hitherto thewater was added to thematerial stepwise in small'amounts to gradually increase the moisf-Lture content to the desired final degree. With this method some grainsabsorb more andthein the end the equalization of the moisture percentageofthev others less water so that equalization of the water content ofthe, grains. The known method of repeatedly wetting the material insmall amounts implies the use ofa number of wetting devices, conveyingmeans and containers, which require control for the number of days whichthe treatment takes, while when strongly wetting the material only-once,

which can be done on a rough scale without accurately determining theamount 'of water applied, or when softening the material as indicated,the numerous wetting and quieting containers can be dispensed'with andit is sufficient to use instead one. simple, container which. can

be continuously controlled in short intervals.

The softening method, moreover, yields the additional advantage thatevery single grain will be completely surrounded with water, which isnotpossible by an intermittent wetting of the material with smallamounts of water, and that 2 to 5% and for particular purposes up to 15%and more water can without any disadvantages be incorporated in thematerial in one single operation within a very short time, for example,in

one hour.

The rapid incorporation of the water can be, accelerated by regulatingthe temperature of the Waterin the softening container. The operationalso allows the moisture to readily penetrate into the core of eachgrain. For the grinding of bread-grain ofthe various kinds it is of thegreatest importance that the structure of the individual grains has beenloosened, i. e. that the-grains possess a certain degreeof mellownessfor friability, in which state they are, easily ground. This mellownessought to be substantially equal for, all grains of-a grain mixture.According to the amount ofladded and incorporated'water there can beattained a corre sponding increase of volume, if the grain is lefttowitself in a ,quieting container for a, certain time until swellingtakesplace. This swelling operation can be performed in atransit cellwithout the application of heat in about 8' to 16 L hours, which dependson the kind and hardness of the grain, or with the application of heatin 1 to 2 hours by providing the quieting container with radiators,which may be heated with the condensation product of the vacuum drier.

In treating, for example, hard well-adhesive wheat the heating must beregulatedin such a manner that the'temperatures in the grain do not riseso high as to deleteriously affect the gluten. The temperatures in thegrains should as a rule not exceed about 35 C. to 40 C. The loosening ofthe structure, i; e. the mellowing'" of the grains, is brought about bythe-vacuumapparatus, which is constructed asa trickling,

drier.

In treating soft little-adhesive wheat, the gluten of which can behardened; mates-amend rated by temperatures between 50 C. and60- C'.,the treatment by heated radiators offers the 1105-; sibility of not onlyswelling the grains but also improving their bakingproperties Theloosening of the structure of the grains, also in this case, is broughtabout by. the vacuum" apparatus as. stated before;

Rye'is preferably heatedjin the swellin'g'opera tion at'temperaturesbetween40 Cl' and 50C. and afterwards likewisesubjected to a finishingtreatment in the vacuum tricklingdrier.

Barley,'if designed to be used for'the production of-ilour;ispreferabl'y causedto swell at temperaturesof 40 C'. and thenheated'in'the same course of operation to 60 Cl andmore; whereby'a partial agglutination of the starchlis' produced; yieldin'g' a'broken-upflour which for: instancey-may serveia's anutrient for children;

In. swelling-corn theitemperatures to be-appli'ed dependion the purpjosefcrtwhich the-zproduct is to be used; First; the :corn grains mustbe-treat' ed so .as to. allow the germ to beeeasily extractedThisIrequ-ires-a thorough loosening and.;-mellow ing -o-f :the.endosperm, which can beattained-the better themore water: iscausedto-tpermeatenthegrains-to thecore. Tothislend the corn is wetted up- -to2.l\per cent of waten- Ifthe corn'is designedcto b'e .used for theproduction of'alcohol or of broken-up nutrients-the heating. ofj'thecorngrains is at first carriedlon" untilfswelling. occurs,-which is at about40C., andlth'en'con tinued in theisamecourse of 'operati'on'lup 'toa'temperature of 80 to 90 C. ,If, howevenrawnonagglutinated'starch'i's'to'be producedfrom the endosperm; the heatingjshould not be carriedbe yond some 40. C. After the heat'treatment re-' dryingis effectedinthe vacuum'apparatusto the moisture content mostiavorable for" grinding;which is "at about 17 percent. The capability of the vacuum apparatus ofextracting from the material large quantities of'moisture at lowesttemperatures" in a most economic way, makes the'outlined' dry method oftreating the corn con siderably superior to the wet method hithertoapplied to the treatment of corn. Y

In the production of "broken-up rice- 1 products the raw rice issubjected-to the swelling method: with a heat treatment at temperaturesfrom 80' to 90- C.- followed by a treatment in the vacuum apparatus; Theheat treatment and succeeding treatment 'in the vacuum apparatus:-of.lwet1 gathered rice yields particularly favorableiresults in respectof the pealing ofthe rices Therricen peel detaches =more=easily andtensions in thesri'ce grain," which. are oftenset up by=a one-sidedi'surface drying in the held by the sun, are balanced: so that lessbreakageoccurs in the drying:

Legumes designed to "be P worked 'intor nutri'errts'i way,,thezoatsbeing sufficientlyywetted submitted to the swelling operationat about 40 C., then heated to temperatures of to C., and there- .5after dried in the vacuum apparatus.

If it is desired to render inactive the enzymes presentin the epidermisand germ of the grain,

this *canbe-attained by a short-time heat treatmentlafter the-wetting orsoftening, care having tube-taken in'this treatment that the inner coreof the grain is not deleteriously affected by the action of the heat.This operation makes it necessary'that the epidermis is amply permeatedwithzwater during the heat treatment and that a sudden cooling can takeplace after the heat treatment.v The operation can most simply-becarried out by 'in'terposin'gi between the soften-v ingjdevic'e and thewashing device heating means inthe form of 'a'h'eated worm conveyor. Insuch operationlthe absorption" of water by. themdividual lgrain's 'isconsiderable' and different," but this difference is? compensated andregulated by passing the material in the final stage or theprocessithrough' the vacuum: apparatus." 1

If, for' certaimkin'ds' or" material and forth products to'b'e obtainedtherefrom; it is "desired to' get 'in the grinding: hardj. granular"and" pure grits andgranular' 'fiOurS".with"gOOd "bakingfprop; erti'es;there "is 'preferably mounted in"thesluice chamber, which serves "to:intro-duce'the material intothe vacuum l apparatus; a heated" worm insuchiwmanner that 'itdsiboth cut "from the at mosphere and fromthevacuum of "theivacuun drier. This can, for instance, be .attained by"twotsuitable. rotary valves: The? materiat is evacuated before it passesinto" the" worm. v In mcvin'g'eontinuously'through the worm; the"ma=teri'al is for a' predetermined" length" oitinie' brought tothe'desired' temperature by heating. the worm shell andintroducinga'predetermined regul'ablequantity of live steam'at negative pressure.For preventing the temperature" in the; core of 1 the grains fromexceeding the critical limit th'e' material is then introduced intothedryiiig compartment of the vacuum drierwherenit. is exposed toa'"high vacuum" and suddenly. "cooled 1 accordingly. In this way thereis'=also"obtained-" a treatment 'of'the epidermis ofthe material, because any further. deleterious heat "influence on the-inner core of thegrains-can be-preventedin the vacuum apparatus.

The -material, suchas bread grain', introduced" into the sluicecompartmentmay-also-"beput' underpressure by admitting livesteam ofhigher pressure for a relatively short period of time: withini'wvhichthebaking properties of thegrain are-notafifected." When the material is.there-- upon" passed into the vacuum compartment it is suddntlyreliev'edot 'thepressure by the vacuum prevailing therein: This suddenexpansion' produ'ces a" looseningof the structure by which the grind-ing*properties are improved. I

The treatment of the material-witlfsteai'n in the sluice compartmen-tof-thevacuum appar ratus also allows of 'dis'embittering certain-=leg.-' umes;- suchas "soya beans, lupines -01" chestnuts;- orobtain-ring" the": enzymatic neutralizaticn or lipases, peroxy'dasesetcin legum'esas=-wel1 Kas the neodorizaticni of musty porn; oats, soyab'eans; eta, if": in succession" to i: the: saidztreatm'enttther aresuifi'ciently wetted and ithenllikewise broken: 75--water; ;the splitbitterzprinciples-Land othetinoxe 4 5. ionscomponents are. removed inthe vacuum apparatus by a kind of vacuum: water-steam I distillation. 1

desired final moisture percentage, takes place in the lower heatingsections, the vapor produced being preferably conducted upwardly as acounter-flow through the grain slowly trickling in downward direction.The Vapor condenses on the grain in the higher layers Where it is stillcold and thus aids in warming the grains and, moreparticularly,softening the epidermis of the grains so as to make-it readily.permeable for the moisturewhen the grains reachthe evaporation zone.-The condensedvapor must be evaporated again and again so that acirculation of vapor is maintained in acertain section of the vacuumdrier, in whichthe calories of the circulating vapor are preserved andfavorably utilized.

1 In drying the grain in vacua the vaporizing process is. physicallybased on the difference of the steam pressures in the unequally moistgrains so that, as well-known, the moist grains .yield their moisturefirst, whereby these grains are gradually brought to amoisturepercentage corresponding to thatof the driest grains. In orderequaliza totutil-ize the circulating vapor as much as possible, thedischargeof the vapor rest to be passed to the condenser is effected atthe top section of the vacuum drier. The amount of vapor dischargedcorresponds to; the amount of water extracted from the grain undertreatment which was contained in the grain in excess-of the desiredmoisture percentage.

, The moisture, equalization by way of a stepwise evaporation of waterfrom the grains containing most moisture and the utilization of thecirculating vapor moving in a prescribed path are only rendered possibleby using the vacuum apparatus as a trickling drier, sinceit is only insuch a drier that water can be evaporated at low temperatures which donot impair the grain.

With the drying in vacua the grains do not shrink or agglomerate, suchas is the case in air drying. On the contrary, they retain the greatervolume produced by the vacuum with an inherent loosening of the grainstructure. Grinding is considerably facilitated by the mellownessattained through the drying in vacua.

As any desired quantity of ,Water can be extracted in the vacuum drierin a single operation, itqis possible to incorporate in the grains anyamount of water in excess of the usual moisture percentage which is heldthe most favorable for thetreatment. This moisture excess is, forexample, 3-to5 per cent for the normal conditions of treatment in themill and may be 5 to per cent for special grinding purposes, such as forthe centrifugal or impact grinding method, while it. is secured by thevacuum drier that the moisture extraction takes place at lowtemperatures at which the baking properties are not impaired.

The cooling of the dried grain can be performed in the lower sluicecompartment which is provided for delivering the dried grain from thedrier. The cooling is obtained by producing in the said compartment avacuum higher than in the drier, the grain being exposed between theinlet-and the outlet of the compartment to the action of thishigh'vacuum for some -minutesj for example, 5 to 10 minutes. i

Cooling may also be efiectedin the vacuum drier itself by passingthrough its lower elements or sections a cooling medium, which is soregu lated as to prevent the deposition of condensed fluid on these.elements, and by so directing part of thevapor developed in the drierthat it is sucked off through the grain to be cooled below the cooling Ielements. The vapor so directed serves as an agent mediating thecooling, since by contact-cooling alone the desired effect cannotbeattained, unless .there are provided .very large cooling surfaceswhich, howevenis uneconomic.

The lower sluice .compartmentcan also be used for imparting to theepidermis of the grams a' certain degree of toughness favorable to theevacuated filled sluice chamber chemicals in the form of gas or dustwhich have a sterilizing effect or are adapted to improve-the bakingproperties,

such as sulphurous acid, methyl formate, ethylene oxide, 'pyrenone,nitric oxide, chlorine, chlorine dioxide etc.

, The accompanying drawing illustratesby Way.

of example, a. diagrammatic illustration of a plant for carrying out themethod according to the invention.

The numerals I, which are filled with the material to be treated passedthrough a cleaning machine 6,'a system of separators l and a peelingmachine 8. In these devices the grain is freed from admixtures, weedgrains and the peel. Arranged in succession to the peeling machine is asoftening device, in

which the material can be strongly wetted or softened. The softeningdevice, consists of a container H) which is provided with a water supplyII and a number of drain' pipes I21 at different heights. These drainpipes allow of establishing any desired water levelin the softeningdevice. The. container Ill enclosesa perforated container l3 whichservestoguide the grain to be wetted or softened through the device. The 1-material continuously supplied at the top of the container l3 forms acolumn of material which gradually moves-through the water of the con-..tainer lil, whereby it is softened for, a more or. a less long time. inthe container H) can be heldat any desired Due to the fact that thewater level, it is possible to regulate within wide limits the watercontents of the material leaving the softening device through a rotaryvalve or gate [4 of known construction. The carrying along.

of water through the gate is not objectionable, because this water canbe utilized in the washing process. The material passes from the gate Hto a heated worm conveyor IS, in which. the epidermis of the grains isquickly heated for a short time. This heat treatment is advantageous forthe treatment to follow since it makes the to accelerate the swellingprocess so that the time of travel of the material through the tank can2, 3, 4, designate four 51105 7. bereduced-to-one ;to twozhours; Thedischarge pipe of the quieting tank:;l8:. opens into ;a.:.vacu-. um,apparatus which. consists .of an inlet sluice I 9; a: :vacuum container:and: an outlet sluice 21.. The vacuum container-of" this apparatuscomprises-three sections: anuppersection'22 for material .to betreated,.. an: intermediate :section 23 for material to-.b'e treatedzanda lower section- 24'for material already-treated; Interposed be tweenthe sections 23- and .2 i'is a: discharge device; 25w by'which 1 thetrickling; movement. of the material-through the vacuum apparatus can beregulated; Arranged between. :the inlet "sluice i9: and. the tvacuumcontainer .20 .is a' subsidiary sluice 26, into which opens a wormconveyor -21 Withiaheated shell. Theother end of the shellheate'dxworm2.! is'provided with another subsidiary sluicee28 to. which". isconnected as sluice 29 corresponding to theinlet sluice I 9 Abranch 30ot the feed-conduit coming from quietingtank l81opens intothe'sluice 29.Owing to this arrangement the. materialirom the tank 1 l8 "may bepassedieither through the inlet sluice l9 intorthevacuum apparatus), 20,2| or by the branch: conduit 30 and the second inlet sluice 29- throughthe-subsidiary sluice 28; the shellheated worm 27 and the subsidiarysluice 26 into! theevacuum container. 232 of f the vacuum apparatus. l9,20, 2|. The second inlet sluice 29, which is provided for specialpurposes; more particularly serves for the treatment of theepidermis of"thematerial in vacua as well as --for the disembitter'ing oi legumes'orthe like. The upper'part of the vacuum container 20"comprises a num'berofh'eati-ngsections -3| and the lower part a -numberof-='cooling"sections 32; The-heat ing mediumfor :the heating sectionsis supplied by thepiping' 33 -and led off bythe piping 34,

while pipings 35 and '36 serve to pass the-cooling medium-:to-"and fromthe cooling "sections; Are

ranged. the vacuum" container '23 for guiding the vaporisha shaft f 31which is -provided with throttle valves 38- which can'be adjusted sothatthe vapor iseither forced to pass 'in counter-flow through-the:down-trickling material or is drawn from the shaft 3'I-through a suctionpipe--39 When the vapor is guided through the "material in counter-flow,a circulacommons produced at the heating-elements 31 i inthe evaporationzone.- If the vapor shaft 37 is =-tightly"closed by-ilaps 4| andthevapor-is to a condenser:

drawn off *at '42 below'the coolingelements-'32,'

the vaporserves as a mediator in the cooling of the material atthe'cooling elements 32. The

suction pipes-39 and- 42 maybe separately'con- Material re-cooled innected to. a; condenser. the-outlet sluice 2 l and beforebeingdischarged therefrom 'may be treated with moist 'airand/orchemicals-in theform of gas'or dust, whereupon the material'may 'b'epassed'for further treatment, through a re-cleaning device '43 to agrindingmachine The-assembly of 1 successive individual apparatus asillustrated in-:the drawing can be pro 'vided :with by-pass'zfeeding\COlldlllliSffOlfithE max-1. terial toaaccount forspecial caseswherer'onesor the other apparatus should not be used; In "practicing,the method according 'to zthecinventi'onithe .vacuum "steam or-warmwater yielded in the vacuum drying operation can be largely utilized forheating'the'radiators. in'the swelling; operation as'well as.in thesofteningaand -washing .operations;

Having thus.described. our invention, what low steam pressure, suddenlyreleasing the pres-'- sure; then vacuum drying the-kernels to-removethe-excess moisture and equalize'the moisture content of the differentkernels-while also in creasing'thefriability of the same, then coolingsaid grain under vacuum; and then subjecting the same-to the actionofdamp-air'sufiiciently to' toughen the epidermis of the kernels .to asuitable extent formilling;

2. A process as in-claim 1, wherein-wateris addedto the graininproportions-0f about 3" to" 5%, and the grain is heatedfor about twominutes at a temperature such as will raise the" temperature of thegrain-to about C.

3. A processas in claim 2, wherein the pool is heated to expedite theswelling.

4. A processes in claim3, wherein the grain after being evacuated isplaced'under steam pressure of about one atmospherefor-about twominutes.

5. A processes in claim 2, wherein'thegrain after'beingevacuated isplaced under steam pressure of about one atmosphere for about twominutes.

6. A process as in claim 2, wherein the current" of grain is passedthrough-a'body'ofwater at the first step.

KARL DIENST. WALDEMAR. DI'ENST.

REFERENCES CITED The following referencesare of record in the file ofthis patent:

UNITED. STATES PATENTS:

Number Name Date i 1,452;87l' Dienst Apr. 24, 1923' 1,920,107 RichardsonJuly 25, 1933 2,200,880 Baer NOV. 12', 1940 2,227,634 Dalin Jan. 7,'1941 2,272,663 Graumann Feb. 10, 1942 2,278,701 Karr Apr.-'7, 19422,560,615 Warner July 17, 1951'=

1. A METHOD FOR CONTINUOUSLY CONDITIONING A MOVING CURRENT OF GRAINCOMPRISING THE STEPS OF PASSING THE CURRENT THROUGH WATER, HEATING THEGRAIN FOR A TIME AND AT A TEMPERATURE SUFFICIENT ONLY TO SOFTEN THEEPIDERMIS OF THE KERNELS, THEN COOLING THE CURRENT OF GRAIN UNDERATMOSPHERIC PRESSURE, THEN DECREASING THE RATE OF FLOW TO PERMIT THEGRAIN TO ACCUMULATE IN A POOL UNTIL THE KERNELS SWELL, THEN PLACING SAIDCURRENT UNDER LOW STEAM PRESSURE, SUDDENLY RELEASING THE PRESSURE, THENVACUUM DRYING THE KERNELS TO REMOVE THE EXCESS MOISTURE AND EQUALIZE THEMOISTURE CONTENT OF THE DIFFERENT KERNALS WHILE ALSO INCREASING THEFRIABILITY OF THE SAME, THEN COOLING SAID GRAIN UNDER VACUUM, AND THENSUBJECTING THE SAME TO THE ACTION OF DAMP AIR SUFFICIENTLY TO TOUGHENTHE EPIDERMIS OF THE KERNELS TO A SUITABLE EXTENT FOR MILLING.